An outstanding issue with respect to hair colorants includes ease of application and concerns over messy application resulting in skin staining and uneven hair color results. Recent trends indicate that consumers find handling of foamed products preferable to gels, creams or liquids.
Foamed products are known to be generated in one of two ways. The first being the use of a compressed gas (aerosols) which are admixed with a composition that is evacuated from a container by the consumer. A commercial example of this would be Kanebo Cosmetics's Simpro hair colorant. GB2188257A discusses a device for dispensing a two-component product, such as shampoos or dyes in a pressurized container and dispensed in the form of foam.
Outstanding issues with pressurized systems such as these examples are that oxidative hair colorants are radically initiated reactions that require sequestration from oxygen or segregation of the developer from the tint components (couplers, primaries, etc.) until use of the hair colorant is desired by the consumer. The sequestering packaging results in expensive, yet ineffective packaging for dispensing the hair colorant due the lack of control of the ratio of tint components to developer components coming out of the pressurized system or ineffective in segregating the hair colorant from oxygen.
The second way to generate a foam product is via a non-pressurized dispenser in the form of a pump foamer or squeeze foamer. A commercial example of a pump foamer would be Youngrace Bubble Hair Color product. A commercial example of a squeeze foamer would be Kao's Prettia Soft Foam Color, Liese Bubble Hair Color or Blaune Foam Color products. See also US 2004/0213752A1. Further, U.S. Pat. No. 7,040,507 discusses a foam-type hair dye apparatus for converting a liquid hair dye into foam.
Pump foamers can be difficult to utilize with oxidative hair colorant composition due to the use of metal parts, such as springs, that are exposed to the oxidative hair colorant composition. Due to the high pH of the dye composition sub-component and presence of an oxidizing agent, the composition reacts with metal parts of the pump mechanism, such as springs, causing damage to the pump foamer and to the composition when oxidized metal ions contaminate the composition.
Therefore, it is a desire to provide an hair colorant product having a liquid hair colorant composition in a manually-actuable, non-aerosol dispenser. Further, there exists a further desire to minimize damage to hair when using hair coloring products while producing good end color results.
It has been found that the reduction or elimination of surfactants from the hair coloring composition can address the outstanding needs of such products and provide further desired benefits. However, a reduction of surfactants from the hair colorant composition cause most perfumes to be insoluble or unstable in the hair colorant compositions due to the hydrophobic nature of perfumes (being essentially oils). Additionally, perfumes may cause premature foam collapse than desired, leaving a liquid rather than a foam in a user's hand. It has been found that careful selection of perfume components via a ClogP criteria results in perfumes that are soluble and stable in the hair colorant composition which is essentially free of surfactants and do not cause foam instability or premature collapse of the foam.